1. Field of the Invention
The present disclosure relates to a voice coil motor.
2. Background of the Invention
Recently, a super small digital camera capable of storing a digital image and a moving image is mounted on a smart phone and a tablet PC. A conventional camera mounted with the smart phone and the tablet PC includes a lens and an image sensor module receiving light having passed the lens. The conventional small camera cannot adjust a gap between the lens and the image sensor module to have a difficulty in realizing a high quality digital image or moving image.
Recently, a VCM (Voice Coil Motor) has been developed to adjust a gap between an image sensor module and a lens of the camera. The conventional VCM includes a bobbin mounted with a lens, a coil mounted at a periphery of the bobbin and a magnet opposite to the coil. A magnetic field generated by applying a current to the coil, and a magnetic field generated by the magnet drive the bobbin to adjust a gap between the image sensor module and the lens of the camera.
However, the conventional VCM is disadvantageous in that the coil is arranged at a periphery of the bobbin to have a difficulty in increasing a wound length of coil and to weaken a driving force of the bobbin, such that the wound length of coil is reduced as size of bobbin increases, whereby it is difficult to increase the size of bobbin and subsequently the size of bobbin.